• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.392-395
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• 2004

A coupler is a microwave passive component used for power coupling or dividing. Regarding the trend of current telecommunication systems it is highly desirable for monolithic integration of passive components as such LTCC(Low temperature cofired ceramics) technology offers potential advantage in size, cost and performance. Utilizing LTCC technology a 1608 size type dual band coupler for DCS and EGSM band was fabricated. Its characteristics such as coupling, insertion loss, isolation and directivity was measured and compared with simulation results.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1949-1960
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• 2003

This paper presents vibration and noise control of flexible structures using squeeze mode electro-rheological mounts. After verifying that the damping force of the ER mount can be controlled by the intensity of the electric fild, two different types of ER squeeze mounts have been devised. Firstly, a small size ER mount to support 3 kg is manufactured and applied to the frame structure to control the vibration. An optimal controller which consists of the velocity and the transmitted force feedback signals is designed and implemented to attenuate both the vibration and the transmitted forces. Secondly, a large size of ER mount to support 200 kg is devised and applied to the shell structure to reduce the radiated noise. Dynamic modeling and controller design are undertaken in order to evaluate noise control performance as well as isolation performance of the transmitted force. The radiated noise from the cylindrical shell is calculated by SYSNOISE using forces which are transmitted to the cylindrical shell through two-stage mounting system.

• Journal of Power System Engineering
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• v.5 no.2
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• pp.87-92
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• 2001

Automotive suspension system is a mechanism for isolation of the vibration coming from the road inputs. Recently, the electronically controlled suspension systems which may improve ride and handling performance have been developed. Here, the continuously controlled semi-active suspension system is focused. As a mechanism to control damping forces continuously, a solenoid valve is used. The modeling for the solenoid valve is introduced briefly, a vehicle dynamics modeling is constructed, and then combined system model is completed. To design the efficient control algorithm for the semiactive suspension system the knowledge based fuzzy logic is applied and the technique how to apply the sky-hook theory to the fuzzy logic is developed. Finally, to confirm the improvement of performance the computer simulation is carried out.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.259-265
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• 2016

In this paper, we present an architecture for the fault isolation by applying virtualization-based multi-stack technologies. We propose the simultaneous sharing and switching mechanism using virtualied serial communications. Each guest OS has its own virtual serial device. The distribution module provides communications between the guest OS's through the virtual serial devices and simultaneously detect the liveness of the guest OS. The suggested mechanism has been implemented in VirtualBox and shows satisfactory performance in transmission speed and data sharing capability with virtual RS232.

• Animal cells and systems
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• v.6 no.1
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• pp.81-84
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• 2002

SINE-R retroposons have been derived from human endogenous retrovirus HERV-K family and found to be hominoid specific. Both SINE-R retroposons and HERV_K family are potentially capable of affecting the expression of closely located genes. Using the genomic DNA from patients with schizophrenia, we identified 26 SINE-R retroposons and analyzed them with the sequences derived from the hominoid primates. The SINE-R retroposons from schizophrenia showed 89.7-96.6％ sequence similarities with the sequence of the schizo-cDNA clone that derived from postmortem tissue from the frontal cortex of an individual suffering from schizophrenial. Phylogenetic analysis using the neighbor-joining method revealed that the new SINE-R retroposons in schizophrenia have proliferated independently during hominid evolution. Such retroposons have great relevance to genomic change connected to human diseases. The data suggest that new SINE-R retroposons identified in schizophrenia deserve further investigation as potential leads on the understanding of neuropsychiatric diseases.

• Animal cells and systems
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• v.2 no.4
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• pp.435-438
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• 1998

In the present study, we have examined the crossability of four species in the A. jaluense complex to provide additional information on their delimitation and levels of differentiation. Crosses between diploid A. chiisanense and the tetraploid species including A. jaluense s. str., A. triphyllum, and A. pseudoproliferum yielded no fruit- or seed-set, indicating that the former species is reproductively completely isolated from the latter three species. In interspecific crosses between the tetraploid species, combinations involving A. jaluense s. str. resulted in much reduced fruit- and seed-set, indicating that A. jaluense s. str. is more or less reproductively isolated from the other tetraploid species. However, crossing data revealed the absence of reproductive isolation between A. triphyllum and A. pseudoproliferum These results strongly support the relationships that have been previously suggested for the A. jaluense complex on the basis of morphology, chromosome number, and flavonoid chemistry.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.469-476
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• 2005

To date, many viable smart base isolation systems have been proposed. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively. A fuzzy logic controller (FLC) is used to modulate the MR damper. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. Neuro-fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find appropriate fuzzy rules and the GA-optimized FLC outperforms not only a passive control strategy but also a human-designed FLC and a conventional semi-active control algorithm.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.15-20
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• 2000

We demonstrated a single balanced mixer of the combination of high-T. superconductor (HTS) and III-V GaAs beam lead Schottky diodes operating in the mini-cryogenic chamber. The HTS hybrid mixer was designed with a center frequency of 27.5 GHz and a bandwidth of 1 GHz, and consisted of a rat-race coupler circuit with beam-lead diodes attached to its balanced ports. The HTS hybrid mixer with 1 GHz RF bandwidths exhibits a conversion loss of 6 dB. A LO-to-RF isolation was greater than 40 dB in the range of operating frequencies. Since the HTS/III-V hybrid mixer devices have lower noise and conversion loss, this technique provide us with new capabilities that can be effectively utilized in the field of local-point distribution service (LMDS) systems.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.39-43
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• 2001

A system, IS-95C coupler that combines the signals of IS-95A/B and IS-95C BTS and compensates the differences between the signals of two systems and connected to optical repeater If no IS-95C coupler exist, Optical repeater can't service of signal balanced. A system carries on combination, amplification, level modulation function of the TX signals(IS-95A/B & IS-95C) and division and level modulation function of the RX signals. Isolation satisfied above 100dB.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.473-477
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• 2003

In this paper, a integrated structure of a two-element microstrip patch antenna with two feeds for GPS/PCS dual-band operation is proposed. The radiating element for PCS operation is a novel broad band low-profile cylindrical monopole top-loaded with a shorted meander patch, which gives linearly polarized conical radiation pattern and size reduction of patch due to meander line. The radiating element for GPS operation is a novel square-ring microstrip patch with truncated corners and slits. which provide circularly polarized broadside radiation patterns and size reduction due to slots. using dielectric substrate in GPS antenna of proposed antenna provide to improve isolation between two feeds and reduce size of patch. The proposed antenna achieves the bandwidth and polarization requirements of GPS and PCS systems.